package cxg.create.mybatis.util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class SqlSessionFactoryUtils {

    private final static Class<SqlSessionFactoryUtils> LOCK = SqlSessionFactoryUtils.class;

    private static SqlSessionFactory sqlSessionFactory = null;

    private SqlSessionFactoryUtils(){

    }

    public static SqlSessionFactory getSqlSessionFactory(){
        synchronized (LOCK){
            if(sqlSessionFactory != null){
                return sqlSessionFactory;
            }
            String resource = "mybatis-config.xml";
            InputStream inputStream;
            try {
                inputStream = Resources.getResourceAsStream(resource);
                sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
            }catch (IOException e){
                e.printStackTrace();
                return null;
            }
        }
        return sqlSessionFactory;
    }

    public static SqlSession openSqlSession(){
        if(sqlSessionFactory == null){
            getSqlSessionFactory();
        }
        return sqlSessionFactory.openSession();
    }

}
